1. Field of the Invention
This invention relates to the field of optical character recognition (OCR). More specifically, this invention relates to generating the proper orientation of an image for application of optical character recognition so that the image may be scanned and converted to text most easily.
2. Background of Related Art
Optical character recognition (OCR) is a field wherein text on hard copy is transformed by a device into text represented in a computer system in a format such as ASCII or a similar encoding. In most prior art systems, this process generally takes several steps. First the hard copy text is converted into a digitized image which may be represented in a computer system. This is done by sampling the image using hardware devices such as light-sensitive charged coupled devices (CCD's) in a camera or flat bed scanner. The camera or scanner has an interface to circuitry which digitizes the image (such as a computer system). Once the image has been digitized, a device having an OCR reader, such as a computer system, converts the digitized image to text. Many such OCR devices are well-known in the art, and one example of such an OCR system is known as the Omnipage.RTM. brand character recognition system available from Caere.RTM. Corporation of Los Gatos, Calif., the assignee of the present invention (Omnipage.RTM. and Caere.RTM. are trademarks of Caere.RTM. Corporation). Such a system may comprise a flat-bed or hand-held scanner which comprises the necessary circuity to transmit the image to a computer system containing the OCR software or firmware and interface circuitry. The computer system then performs the digitizing and OCR functions. One such computer system which may be used in prior art OCR applications is known as the Macintosh.RTM. family of personal computers, such as the Macintosh.RTM. II, or Macintosh.RTM. SE 30 brand computer system available from Apple.RTM. Computer, Inc. of Cupertino, Calif. (Macintosh.RTM. and Apple.RTM. are registered trademarks of Apple.RTM. Computer, Inc.).
One shortcoming of prior art OCR systems is that the hard copy must be oriented in a certain way with respect to the scanner in order for OCR to be performed properly. In other words, the OCR system does not know the orientation of the input image. The user is relied upon to ensure that the hard copy is oriented properly in relation to the scanner for OCR to take place. The OCR system may require that the user scan left-to-right, right-to-left, up-to-down, or down-to-up. If the image is not oriented properly with respect to the scanner, the image may appear upside down or perpendicular to the proper line-of-sight that the OCR system expects. This will result in the inability of the OCR system to generate proper text data because the characters in the text appears sideways or upside down to the OCR system. The system relies upon the user to ensure that he is scanning in the proper direction, and scanning such that the image is oriented properly. In summary, prior art scanners do not have the ability of re-orienting the scanned image in order to perform OCR properly.